THE UNIVERSITY OF VIRGINIA KNOWS STORMWATER

The Dell at the University of Virginia

The pond at the Dell is not only just a peaceful place to study or relax, the pond actually serves a purpose. The pond was installed to improve the water quality and flow characteristics of Meadow Creek, which is a severely impacted stream. Meadow Creek suffers from degraded water quality and flashy flow conditions. The water quality has been degraded by nutrients, iron, and coliform bacteria, which includes fecal coliform found in human and animal waste.

The restored stream channel upstream of the pond was recreated to provide the maximum possible oxygenation of the water in Meadow Creek. The recreated stream has all of the physical properties of natural streams, including meanders and floodplains, vegetative swales and riparian buffers. The swales and buffers prevent erosion and filter pollutants and particulate matter from the stream flow. The floodplains serve as an area for stormwater retention as well as cleansing of the water.

The pond serves two main purposes. First, it removes sediment by settling. Water flowing at a high velocity can carry much more sediment than a slowly moving water. By the time water entering the pond has made its way to the outfall, the water velocity has been greatly decreased and therefore most of the sediment that was carried by the stream has been settled out. The pond forebay is designed to remove the bulk of the sediment and will be cleaned out periodically. Secondly, the main pond provides sufficient detention to allow for the natural biological cleansing of the water and settling of the finer sediment.

People in both the University and local communty have responded positively to the stream daylighting and creation of the pond. Some people even offer suggestions for ways the University can take the pond a step further and create a wildlife sanctuary for geese and other aquatic birds. While occasional visits to the pond by migratory birds are acceptable, full time habitation by geese is discouraged. The recreated stream channel and pond cannot support geese. If geese were to take up residence in and around the pond, they would further degrade the quality of the water by adding fecal bacteria and nutrients to the water. The addition of geese to the pond would increase the very problems that the pond is intended to remediate.